Lake Ontario is the smallest and most eastern of the five great lakes. It forms an important link in the St Lawrence Seaway system. The lake lies between the Canadian province of Ontario and the northwestern part of New York. It is about 193 miles long and 53 miles wide, covering an area of 7520 square miles, more than six times the size of Rhode Island.
Lake Ontario does not freeze in winter, except along the shore where the water is more shallow. The lake has a moderating effect on the climate of the surrounding area.
Lake Ontario empties into the Atlantic Ocean through the Saint Lawrence River.
Major ports on Lake Ontario include Rochester in New York and Hamilton and Toronto in Ontario.